Buggy code:
public class ClassUtilsTests extends TestCase { public void setUp ( ) { } public void testIsPresent ( ) throws Exception { } public void testForName ( ) throws ClassNotFoundException { } public void testForNameWithPrimitiveClasses ( ) throws ClassNotFoundException { } public void testForNameWithPrimitiveArrays ( ) throws ClassNotFoundException { } public void testForNameWithPrimitiveArraysInternalName ( ) throws ClassNotFoundException { } public void testGetShortName ( ) { } public void testGetShortNameForObjectArrayClass ( ) { } public void testGetShortNameForMultiDimensionalObjectArrayClass ( ) { } public void testGetShortNameForPrimitiveArrayClass ( ) { } public void testGetShortNameForMultiDimensionalPrimitiveArrayClass ( ) { } public void testGetShortNameForInnerClass ( ) { } public void testGetShortNameForCglibClass ( ) { } public void testGetShortNameAsProperty ( ) { } public void testGetClassFileName ( ) { } public void testGetPackageName ( ) { } public void testGetQualifiedName ( ) { } public void testGetQualifiedNameForObjectArrayClass ( ) { } public void testGetQualifiedNameForMultiDimensionalObjectArrayClass ( ) { } public void testGetQualifiedNameForPrimitiveArrayClass ( ) { } public void testGetQualifiedNameForMultiDimensionalPrimitiveArrayClass ( ) { } public void testHasMethod ( ) throws Exception { } public void testGetMethodIfAvailable ( ) throws Exception { } public void testGetMethodCountForName ( ) { } public void testCountOverloadedMethods ( ) { } public void testNoArgsStaticMethod ( ) throws IllegalAccessException , InvocationTargetException { } public void testArgsStaticMethod ( ) throws IllegalAccessException , InvocationTargetException { } public void testOverloadedStaticMethod ( ) throws IllegalAccessException , InvocationTargetException { } public void testClassPackageAsResourcePath ( ) { } public void testAddResourcePathToPackagePath ( ) { } public void testGetAllInterfaces ( ) { } public void testClassNamesToString ( ) { List ifcs = new LinkedList ( ) ; ifcs . add ( Serializable . class ) ; ifcs . add ( Runnable . class ) ; assertEquals ( "[interface<seq2seq4repair_space>java.io.Serializable,<seq2seq4repair_space>interface<seq2seq4repair_space>java.lang.Runnable]" , ifcs . toString ( ) ) ; assertEquals ( "[java.io.Serializable,<seq2seq4repair_space>java.lang.Runnable]" , ClassUtils . classNamesToString ( ifcs ) ) ; List classes = new LinkedList ( ) ; classes . add ( LinkedList . class ) ; classes . add ( Integer . class ) ; assertEquals ( "[class<seq2seq4repair_space>java.util.LinkedList,<seq2seq4repair_space>class<seq2seq4repair_space>java.lang.Integer]" , classes . toString ( ) ) ; assertEquals ( "[java.util.LinkedList,<seq2seq4repair_space>java.lang.Integer]" , ClassUtils . classNamesToString ( classes ) ) ; assertEquals ( "[interface<seq2seq4repair_space>java.util.List]" , Collections . singletonList ( List . class ) . toString ( ) ) ; <START_BUG> assertEquals ( "[java.util.List]" , ClassUtils . classNamesToString ( Collections . singletonList ( List . class ) ) ) ; <END_BUG> assertEquals ( "[]" , Collections . EMPTY_LIST . toString ( ) ) ; assertEquals ( "[]" , ClassUtils . classNamesToString ( Collections . EMPTY_LIST ) ) ; } public static class InnerClass { static boolean noArgCalled ; static boolean argCalled ; static boolean overloadedCalled ; public static void staticMethod ( ) { } public static void staticMethod ( String anArg ) { } public static void argStaticMethod ( String anArg ) { } } private static class OverloadedMethodsClass { public void print ( String messages ) { } public void print ( String [ ] messages ) { } } private static class SubOverloadedMethodsClass extends ClassUtilsTests . OverloadedMethodsClass { public void print ( String header , String [ ] messages ) { } void print ( String header , String [ ] messages , String footer ) { } } }

Fix:
assertEquals ( "[java.util.List]" , ClassUtils . classNamesToString ( List . class ) ) ;